1. Field of the Invention
The invention relates to latches. More particularly, the invention relates to latches which are engageable and disenageable from an easily accessible area to an otherwise inaccessible area such as when a latch is actuatable from a front of a container and the latch hook is on the side of the container, the side of the container being obscured by other containers.
2. Prior Art
In the ensuing discussion the types of latches described are generally referred to as front opening latches since the first surface perceived by a user is considered to be the "front" of the container. In the discussion of the prior art hereunder and in the discussion of the invention, the term "front" is used generically to indicate the exposed surface of the container. This could actually be, however, any surface of the container.
Front opening latches of the prior art have been developed for the same purpose as the present invention; that is to allow operation of the latch where containers are stacked next to one another obstructing access to the sides of the container. Since other conventional latches reside on the side of the container or require movement out of the plane of the side of the container, operation of these would be severely impeded.
Two main categories of prior art latches are intended to satisfy the desire/requirement for front operation latches. These are 1) side mounted latches that are operable when access to box sides is limited and 2) top mounted latches.
In the first category (side mounted), an example of an arguably "front only" actuatable latch is known by the trade name "Hook Lock" and is illustrated in FIG. 1 of this application. One of skill in the art will recognize this latch. The latch incorporates a cam design so that movement of the handle lever causes both an arcuate and a radial movement of the hook. Thus, upon moving the handle lever in the appropriate direction the hook moves into engagement with the keeper plate. Further movement of the lever in the same direction causes the hook to draw the keeper plate toward the cam of the handle lever. This action draws the container cover toward its base and provides a tight closure. The latch is sold as actuatable from the front only because if mounted in a recess in the container side, it is considered possible to slide one's finger between adjacent containers and actuate the latch without actually seeing more than the end of the lever. Clearly, this suffers the substantial drawback that the latch could not be actuated in this manner if the cover of the container was deep. If it were, the fingers of the user would not reach the latch. Thus, this type of latch is not a viable solution to the front only operation dilemma.
Top mounted latches provide more diversity in the front only operation forum since they truly operate from the exposed surface of the container. Prior art top mounted latches have certain inherent drawbacks with some types of containers (e.g., fluid tight containers). These latches thus leave the art searching for a better solution to the need for front only operation.
One type of top mounting latch is a bail spring latch such as that illustrated in FIG. 2 of the disclosure. This type of latch, although effective in closing and tensioning a container lid, requires a "through the container" mounting. In containers commonly employed for transport of sensitive equipment where a fluid tight seal is required at all times, these latches require a very effective (expensive) dynamic seal. Dynamic seals of this nature are cost prohibitive, subject to failure and therefore do not provide a preferred solution.
Other prior art latches whether top or side mounted which operate well for their intended purpose cannot work where adjacent structures are concerned because of their requirement that they move out of the side plane of the container or where they don't, they simply cannot be easily actuated from the exposed surface of the container. The adjacent structure inhibits the movement and/or access to these latches and prevents operation thereof.